1. Field of the Invention
The present invention relates to an image forming apparatus for conducting an interruption operation.
2. Description of the Related Art
In a case where a conventional image forming apparatus (e.g., printer) receives a printing request (latest printing request) in the midst of executing an accepted printing job corresponding to a previously received printing request (former printing request), the printing job corresponding to the latest printing request is executed after the image forming apparatus has finished executing all of the accepted printing jobs corresponding to former printing requests received before receiving the latter printing request. That is, in a case where there is an urgent printing job, all of the unfinished accepted printing jobs corresponding to previously received printing requests are to be cancelled in order for the urgent printing job to be executed. Accordingly, it is desired for an image forming apparatus to prioritize execution of a designated printing job without having to cancel all of the accepted printing jobs.
As one example, Japanese Laid-Open Patent Application No. 2003-118209 discloses a job management apparatus in which a required job type can be executed preferentially for individual jobs with a priority attached. Japanese Laid-Open Patent Application No. 2003-118209 describes that the job management apparatus is for managing plural jobs. The job management apparatus includes a priority job designating part for designating a job to be executed preferentially for individual jobs and a priority job registering part for registering a job which is to be preferentially executed with respect to the job designated by the priority job designating part.
Although the job management apparatus can change the job execution order by attaching priorities to individual jobs, in an actual image forming apparatus, it is difficult to interrupt a job and initiate a PDL (Page Description Language) process when the PDL process is already being executed for another job.